Skip to content
worldfires
en
UA · Ukraine · –

Sloviansk fire, 20 May 2026 Слов'янський район · Sloviansk

Out · last detection 20 May 2026, 10:48 UTC

The fire started on 20 May 2026 in Sloviansk, Ukraine, and satellites saw it burning for 2 days. Copernicus mapped a burnt perimeter of 107 hectares from satellite imagery, spread across a single municipality.

It is the 925th largest in Donetsk Oblast since 2016 (of 1004 with a page). Number 917 in Ukraine in 2026, of 984.

The power measured by the satellite is low (4.6 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Sloviansk · 2026Sloviansk · 2022Sloviansk · 2025Sloviansk · 2024

Burnt area
107ha
Copernicus perimeter
Duration
≈ 2days
20 May 2026 – 21 May 2026
Municipalities hit
1
districts
Started on
20 May
2026
Heat detections
1
in a single hotspot: 5 MW
Danger at start
21
Moderate · FWI index
Average daily power
5MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 20 May21 May

How it evolved, day by day

20 May 2026 · 5 MW · 1

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

31°high
53km/h · peak gust
16%lowest humidity

It had gone 2 days without rain (1 mm or more) when it started. Rain came after the fire: 1.4 mm on 23 May.

This area had burned before

2% of the perimeter overlaps earlier fires recorded since 2016: 2 ha in 2025.

What happened to each town

  1. Sloviansk Слов'янський район 3.3 km from the centre where it started
    107 ha reached on 20 May
    0.1 %

Burnt area inside each municipality, from crossing the official perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.

What burned

  • Mixed forest80 %
  • Other natural land15 %
  • Coniferous forest5.6 %

Land cover inside the perimeter as reported by Copernicus EFFIS (outside the Corine Land Cover area).

The weather day by day

ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.

Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

Started with Strong wind: 21 % of the area in Ukraine

Day High Min. humidity Peak gust Rain Danger (FWI)
20 May 28.4 °C 37 % 53 km/h 0.5 mm Moderate 21
21 May 30.9 °C 16 % 47 km/h 0.0 mm High 28
22 May after 31.7 °C 21 % 34 km/h 0.0 mm High 25
23 May after 27.7 °C 38 % 20 km/h 1.4 mm Low 8

Its twins: fires that started in the same weather

It started with an FWI of 21.2, a minimum humidity of 37% and 2 days without rain. Fires in the area that started in weather like this since 2016: 28.

FWI at the start 21.2
Minimum humidity 37 %
Days without rain 2
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Sloviansk fire, June 2026
212 ha 10 days FWI 21.1 Min. humidity 37 % 1 km away, in 2026

First rain (1 mm or more) after it ended: 8.4 mm on 4 Jul.

See its page Compare with this fire

What happened to them

4 days
median duration
182 ha
median area
0 %
went past 1,000 ha
4.6 mm
rain at the end (median; 22 of 28 had it)

It stayed below its twins: 107 ha against a median of 182 ha. It lasted 2 days, against 4 days.

In 6 of 28, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 4.6 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

1.4 mmfirst rain
23 May2 days after it ended
53km/h · max. gust

It was considered over on 21 May, and on 23 May 1.4 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 22 of 28, with a median of 4.6 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 13 May 2026
After · 28 May 2026

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 19 May 2026 the air beside the fire reached 17 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak17 µg/m³
Days over the guideline0 days
PM1026 µg/m³
Optical depth0.46
18 May20 May22 May
Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 1Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Ukraine

Frequently asked questions

How long did the Sloviansk fire last?
The official perimeter only gives the start date (20 May 2026). The end comes from the heat detections inside the perimeter: it burned until 21 May 2026 (2 days from 20 May 2026), the last day with detections before more than 10 days in a row without any, so it is approximate.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 107 hectares (1.1 km²). Official national figures may differ.
Which municipalities burned?
The fire only entered Sloviansk (107 ha, 0.1 %).
Did the fire reach a town?
The fire started in Sloviansk and came within 3.3 km of its centre. That is the distance from the perimeter, or the nearest hotspot, to the point marking the centre; it does not mean it entered the houses.
What was the weather like?
During the fire the temperature reached 30.9 °C, humidity dropped to 16 % and gusts hit 53 km/h. The fire danger index (FWI) reached 28, class High.
Where does this data come from?
From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Ukraine (geoBoundaries). It is not an official report.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 28. Their median duration was 4 days and their median area 182 ha; 0 % went past 1,000 ha. In 6 of 28, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 4.6 mm.

Where to verify it

A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.

Emergency number: 101 · 112 · Emergency number and official warnings

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

RSS Changes to this page With cross-checks and a citable version

Does something look wrong on this page?

This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.

Report an error
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 101 · 112.

How we know this
  • Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
  • The official perimeter has no end date: the end is the last day with VIIRS detections inside the perimeter before a gap of more than 10 days (150 days at most), so it is approximate. One Suomi-NPP VIIRS detection on those dates.
  • We have not matched this page with any official record.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.

How we build fire pages: methodology

Where this data comes from

The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM2 (Public Domain). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.